Sphygmograph



FIG. 1 is a front, bottom and right perspective view of a sphygmograph showing our new design;

FIG. 2 is a rear, top and left perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view, a left side view being a mirror image thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a perspective view thereof showing a state that a cover is opened; and,

FIG. 9 is a reference view thereof showing a using state that the sphygmograph is attached to a finger tip represented by dotted lines.

The broken lines in FIG. 9 represent environmental subject matters and form no part of the claimed design. 

The ornamental design for a sphygmograph, as shown and described. 